Astronaut Luca Parmitano captured from ISS the Richat Structurein Mauritania.

Credit: Luca Parmitano, ESA, NASA

The Richat Structure, also called Guelb er Richât (Arabic قلب الريشات Qalb ar-Rīšāt), the Eye of Africa, or Eye of the Sahara, is a prominent circular feature in the Sahara’s Adrar Plateau, near Ouadane, west–central Mauritania, Northwest Africa. It is an eroded dome, 40km in diameter, exposing sedimentary rock in layers which appear as concentric rings. Igneous rock is exposed inside and there are spectacular rhyolites and gabbros which have undergone hydrothermal alteration and a central megabreccia. The structure is also the location of exceptional accumulations of Acheulean archaeological artifacts.

The local scenery on the ground is as follows.

Credit: Wikipedia

Reference: Luca Parmitano’s Tweet
See earthview photo gallery: LiVEARTH